1. Field of Invention
The present invention relates to an electric current overload protection device, and more particular to a protection device that is also capable of detecting and preventing circuit failure due to high temperature.
2. Description of the Related Art
With reference to FIG. 5, an overload protection device used for an electric circuit board has a brace (90), two ports (92), a temperature sensing element (93), a knife-break switch (94), and a current overload fuse (96). The two ports (92) are separately mounted on the brace (90). The temperature sensing element (93) is a rod made from a high thermal expansion material and is mounted between the ports (92). The knife-break switch (94) is mounted between the two ports (92) and has a pivotal end and a distal end. The distal end of the knife-break switch (94) selectively contacts one of the ports (92). The pivotal end of the knife-break switch (94) is electronically connected to the other port (92) with using the current overload fuse (96). During use, the overload protection device is electrically connected in a circuit loop with the ports (92) and the temperature sensing element (93) is attached to a heat generating element of the circuit loop. Thus, the overload protection device may break thus to protect the circuit loop either when temperature abnormally increases or when the current overload occurs.
Although the aforementioned overload protection device may provide the circuit loop with the high temperature and overload current protection, the overload protection device still has disadvantages. For instance, an installation angle of the overload protection device is limited since the knife-break switch cannot function up side down. Moreover, many elements are required in the overload protection device, thus manufacturing complexity and costs are not satisfactory.
The present invention provides a current and temperature overload protection device that has a simplified structure without limitation to installation orientation.